FDA, CDC Urge Pause of J&J COVID Vaccine

Damian McNamara


April 13, 2021

Updated 3:25 pm, April 13, 2021

Editor's note: Find the latest COVID-19 news and guidance in Medscape's Coronavirus Resource Center.

The FDA and CDC have recommended that use of the Johnson & Johnson COVID-19 vaccine be paused after reports of blood clots in patients receiving the shot, the agencies announced Tuesday.

The pause is intended to give time to alert the public to this "very rare" condition, experts said during a joint media briefing by the FDA and CDC April 10.

"It was clear to us that we needed to alert the public," Janet Woodcock, MD, acting FDA commissioner said. The move also will allow "time for the healthcare community to learn what they need to know about how to diagnose, treat, and report" any additional cases.

The move was prompted by six reported cases of central venous sinus thrombosis (CVST) and thrombocytopenia in the first 2 weeks after administration of the vaccine.

No reports of similar events have been reported following administration of the Pfizer/BioNTech or Moderna vaccines.

Of the six reported cases linked to the J&J vaccine, all in women between the ages of 18 and 48 years, one woman died and another ended up in critical condition.

"I know the information today will be very concerning to Americans who have already received the Johnson and Johnson vaccine," said Anne Schuchat, MD, principal deputy director at the Centers for Disease Control and Prevention.

"For people who got the vaccine more than one month ago, the risk is very low at this time," she added. "For people who recently got the vaccine, in the last couple of weeks, look for symptoms."

Headache, leg pain, abdominal pain, and shortness of breath were among the reported symptoms. All six cases arose within 6 to 13 days of receipt of the Johnson and Johnson vaccine.

Traditional Treatment Dangerous

Importantly, treatment for traditional clotting disorders, such as heparin, are contraindicated in this syndrome. "The issue here with these types of blood clots is that if one administers the standard treatment we give for blood clots, one can cause tremendous harm or it can be fatal," said Peter Marks, MD, PhD, director of the FDA Center for Biologics Evaluation and Research.

If healthcare providers see people with these symptoms in the presence of low platelet count or blood clots, they should ask about any recent vaccinations, he added.

Headache is a common side effect of COVID-19 vaccination, Marks said, but it typically arises with a day or 2. In contrast, the headaches associated with these events arose about 1 to 2 weeks later and were very severe.

Not all of the six women involved in the events had a predisposing condition or risk factor, Schuchat said.

It is difficult to generalize on any risk factors or subpopulations who might be at higher risk at this point based on six reports, Schuchat said. "The numbers are small enough not to generalize but large enough that we wanted to take a pause."

Severe but 'Extremely Rare'

To put the numbers in context, the six reported events occurred among millions of people who received the Johnson and Johnson vaccine to date.

"There have been six reports of a severe stroke-like illness due to low platelet count and more than six million doses of the Johnson and Johnson vaccine have been administered so far," Schuchat said.

"I would like to stress these events are extremely rare," Woodcock said, "but we take all reports of adverse events after vaccination very seriously."

The Company Response

Johnson & Johnson in a statement said, "We are aware of an extremely rare disorder involving people with blood clots in combination with low platelets in a small number of individuals who have received our COVID-19 vaccine. The United States Centers for Disease Control (CDC) and Food and Drug Administration (FDA) are reviewing data involving six reported US cases out of more than 6.8 million doses administered. Out of an abundance of caution, the CDC and FDA have recommended a pause in the use of our vaccine."

The company said they are also reviewing these cases with European regulators and "we have made the decision to proactively delay the rollout of our vaccine in Europe."

Overall Vaccinations Continuing Apace

"This announcement will not have a significant impact on our vaccination plan: Johnson & Johnson vaccine makes up less than 5% of the recorded shots in arms in the United States to date," Jeff Zients, White House COVID-19 Response coordinator, said in a statement.

"Based on actions taken by the President earlier this year, the United States has secured enough Pfizer and Moderna doses for 300 million Americans…. We are working now with our state and federal partners to get anyone scheduled for a J&J vaccine quickly rescheduled for a Pfizer or Moderna vaccine," he added.

The likely duration of the pause remains unclear, but it will likely be deliberated at a CDC Advisory Committee on Vaccine Practices (ACIP) meeting scheduled for tomorrow to further evaluate the details of these reported events.

The FDA plans to update the information sheets on COVID-19 vaccination for the public and healthcare professionals to reflect information related to the pause.

“This would appear to be a highly precautionary move by the US agencies," said Peter English, MD, immediate past chair of the British Medical Association Public Health Medicine Committee.

“The alert related to the AstraZeneca vaccine, where a similar association is considered possible, will have raised awareness of a possible association with other vaccines," he said. "Nevertheless, the fact that such a small possible risk has been identified is very reassuring — it shows that pharmacovigilance systems are working,"

"I know this has been a long and difficult pandemic, and people are tired of the steps they have to take," Schuchat said. "Steps taken today make sure the healthcare system is ready to diagnose, treat, and report [any additional cases] and the public has the information necessary to stay safe."

Damian McNamara is a staff journalist based in Miami. He covers a wide range of medical specialties, including infectious diseases, gastroenterology and critical care. Follow Damian on Twitter:  @MedReporter.

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